#! /usr/bin/env python

# Update expectations in an Autotest test suite.

# Copyright (C) 2019-2020 Free Software Foundation, Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
# Written by Akim Demaille.

# usage:
#
#    update-test _build/8d/tests/testsuite.dir/*/testsuite.log
#
# from your source tree.
import argparse
import os
import re


def getargs():
    p = argparse.ArgumentParser(description='Update test cases.')
    opt = p.add_argument
    opt('logs', metavar='log', nargs='+', type=str, default=None,
        help='log files to process')
    opt('-v', '--verbose', action='store_true',
        help='Be verbose')
    return p.parse_args()

args = getargs()
subst = dict()


def trace(*args_):
    if args.verbose:
        print(*args_)


def contents(file):
    '''The contents of a file.'''
    trace(file)
    f = open(file)
    return f.read()


def diff_to_re(match):
    '''Convert a portion of patch into a regex substitution to perform.
    No longer used, we now use the expected/effective parts.
    '''
    frm = []
    to = []
    is_diff = False
    for l in match.group(1).splitlines():
        print(l)
        # t in [-+ ]
        t = l[0]
        l = l[1:]
        if t in ['-', ' ']:
            is_diff = True
            frm.append(l)
        if t in ['+', ' ']:
            is_diff = True
            to.append(l)
    if is_diff:
        frm = "\n".join(frm)
        to = "\n".join(to)
        subst[frm] = to


def update(at_file, logfile):
    test = contents(at_file)
    if os.path.isfile(logfile):
        trace("LOG: ", logfile)
        l = contents(logfile)
        trace("LOG: ", l)
        global subst
        subst = {}
        re.sub(r'(?:^@@.*\n)((?:^[-+ ].*\n)+)',
               diff_to_re, l, flags = re.MULTILINE)
        print(subst)
        if subst:
            # Turn "subst{frm} -> to" into a large RE.
            frm = '|'.join([re.escape(x) for x in subst])
            trace("FROM:", frm)
            test = re.sub("(" + frm + ")",
                          lambda m: subst[m.group(1)],
                          test, flags=re.MULTILINE)
    open(at_file, 'w').write(test)


def process(logfile):
    log = contents(logfile)
    # Look for the file to update.
    m = re.search(r'^\d+\. ([-\w]+\.at):\d+: ', log, re.MULTILINE)
    if not m:
        trace("no diff found:", logfile)
        return
    at_file = 'tests/' + m.group(1)
    print(at_file)
    update(at_file, logfile)

for logfile in args.logs:
    trace("FILE:", logfile)
    process(logfile)
